1. Field of the Invention
The present invention relates to a film forming method of forming a metal-containing film on a substrate, a non-transitory computer storage medium, and a film forming apparatus for executing the film forming method.
This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2012-274863, filed in Japan on Dec. 17, 2012, the entire contents of which are incorporated herein by reference.
2. Description of the Related Art
In a photolithography process in a manufacturing process of a semiconductor device, for example, a resist coating treatment of applying a resist solution onto a semiconductor wafer (hereinafter, referred to as a “wafer”) to form a resist film, exposure processing of irradiating the resist film on the wafer front surface with light in a predetermined pattern to expose the resist film, a developing treatment of developing the inside of the exposed resist film and so on are performed in sequence to form a predetermined resist pattern in the resist film on the wafer front surface.
The semiconductor device in recent years is miniaturized to be, for example, 20 nm or less, and the above-described resist pattern is desired to be miniaturized. To cope with the miniaturization of the resist pattern, a so-called multi-patterning in which a plurality of times of resist coating treatment, exposure processing and developing treatment are performed, for example, in the photolithography process is discussed. However, the process of the multi-patterning is complicated, so that when performing etching treatment using a resist pattern formed by the multi-patterning, it becomes more difficult to secure the precision of the etching technique.
Hence, to improve the precision of the etching technique, it is discussed that a metal hard mask film capable of providing an etching selection ratio with respect to a film to be etched is formed as a lower layer of the resist film. The metal hard mask film is a film containing a metal component in an organic film (Japanese Laid-open Patent Publication No. 2001-272786).
Further, for forming the metal hard mask film, it is discussed to employ a so-called spin coating method in terms of cost, flatness of the film and so on. In the spin coating method, a metal hard mask material is applied to the front surface of the wafer by supplying the metal hard mask material onto the wafer during rotation and diffusing the metal hard mask material on the wafer by the centrifugal force.
Incidentally, for example, in a semiconductor device in a multilayer wiring structure, a predetermined pattern of a SiO2 film or the like has been formed on the wafer in some cases. When trying to form on the wafer on which the predetermined pattern has been formed a metal hard mask film using the aforementioned spin coating method, it is impossible to cause the metal hard mask material to appropriately enter grooves of the pattern because the metal hard mask material has a metal component and is poor in fluidity. Along with the miniaturization of the pattern in recent years, the problem of the embedding property of the metal hard mask material becomes prominent. Further, the pattern may be broken at the time of embedding due to the material stress of the metal hard mask material. When the metal hard mask material is not appropriately embedded as described above, it is impossible to appropriately form a metal hard mask film.
The present invention has been made in consideration of the above points and its object is to appropriately form a metal-containing film containing metal on a substrate.